feat(registration): add email domain whitelist policy

frontend/src/utils/__tests__/authError.spec.ts

@@ -0,0 +1,47 @@
+import { describe, expect, it } from 'vitest'
+import { buildAuthErrorMessage } from '@/utils/authError'
+
+describe('buildAuthErrorMessage', () => {
+  it('prefers response detail message when available', () => {
+    const message = buildAuthErrorMessage(
+      {
+        response: {
+          data: {
+            detail: 'detailed message',
+            message: 'plain message'
+          }
+        },
+      },
+      { fallback: 'fallback' }
+    )
+    expect(message).toBe('detailed message')
+  })
+
+  it('falls back to response message when detail is unavailable', () => {
+    const message = buildAuthErrorMessage(
+      {
+        response: {
+          data: {
+            message: 'plain message'
+          }
+        },
+      },
+      { fallback: 'fallback' }
+    )
+    expect(message).toBe('plain message')
+  })
+
+  it('falls back to error.message when response payload is unavailable', () => {
+    const message = buildAuthErrorMessage(
+      {
+        message: 'error message'
+      },
+      { fallback: 'fallback' }
+    )
+    expect(message).toBe('error message')
+  })
+
+  it('uses fallback when no message can be extracted', () => {
+    expect(buildAuthErrorMessage({}, { fallback: 'fallback' })).toBe('fallback')
+  })
+})

frontend/src/utils/__tests__/registrationEmailPolicy.spec.ts

@@ -0,0 +1,77 @@
+import { describe, expect, it } from 'vitest'
+import {
+  isRegistrationEmailSuffixAllowed,
+  isRegistrationEmailSuffixDomainValid,
+  normalizeRegistrationEmailSuffixDomain,
+  normalizeRegistrationEmailSuffixDomains,
+  normalizeRegistrationEmailSuffixWhitelist,
+  parseRegistrationEmailSuffixWhitelistInput
+} from '@/utils/registrationEmailPolicy'
+
+describe('registrationEmailPolicy utils', () => {
+  it('normalizeRegistrationEmailSuffixDomain lowercases, strips @, and ignores invalid chars', () => {
+    expect(normalizeRegistrationEmailSuffixDomain(' @Exa!mple.COM ')).toBe('example.com')
+  })
+
+  it('normalizeRegistrationEmailSuffixDomains deduplicates normalized domains', () => {
+    expect(
+      normalizeRegistrationEmailSuffixDomains([
+        '@example.com',
+        'Example.com',
+        '',
+        '-invalid.com',
+        'foo..bar.com',
+        ' @foo.bar ',
+        '@foo.bar'
+      ])
+    ).toEqual(['example.com', 'foo.bar'])
+  })
+
+  it('parseRegistrationEmailSuffixWhitelistInput supports separators and deduplicates', () => {
+    const input = '\n  @example.com,example.com，@foo.bar\t@FOO.bar  '
+    expect(parseRegistrationEmailSuffixWhitelistInput(input)).toEqual(['example.com', 'foo.bar'])
+  })
+
+  it('parseRegistrationEmailSuffixWhitelistInput drops tokens containing invalid chars', () => {
+    const input = '@exa!mple.com, @foo.bar, @bad#token.com, @ok-domain.com'
+    expect(parseRegistrationEmailSuffixWhitelistInput(input)).toEqual(['foo.bar', 'ok-domain.com'])
+  })
+
+  it('parseRegistrationEmailSuffixWhitelistInput drops structurally invalid domains', () => {
+    const input = '@-bad.com, @foo..bar.com, @foo.bar, @xn--ok.com'
+    expect(parseRegistrationEmailSuffixWhitelistInput(input)).toEqual(['foo.bar', 'xn--ok.com'])
+  })
+
+  it('parseRegistrationEmailSuffixWhitelistInput returns empty list for blank input', () => {
+    expect(parseRegistrationEmailSuffixWhitelistInput('   \n \n')).toEqual([])
+  })
+
+  it('normalizeRegistrationEmailSuffixWhitelist returns canonical @domain list', () => {
+    expect(
+      normalizeRegistrationEmailSuffixWhitelist([
+        '@Example.com',
+        'foo.bar',
+        '',
+        '-invalid.com',
+        ' @foo.bar '
+      ])
+    ).toEqual(['@example.com', '@foo.bar'])
+  })
+
+  it('isRegistrationEmailSuffixDomainValid matches backend-compatible domain rules', () => {
+    expect(isRegistrationEmailSuffixDomainValid('example.com')).toBe(true)
+    expect(isRegistrationEmailSuffixDomainValid('foo-bar.example.com')).toBe(true)
+    expect(isRegistrationEmailSuffixDomainValid('-bad.com')).toBe(false)
+    expect(isRegistrationEmailSuffixDomainValid('foo..bar.com')).toBe(false)
+    expect(isRegistrationEmailSuffixDomainValid('localhost')).toBe(false)
+  })
+
+  it('isRegistrationEmailSuffixAllowed allows any email when whitelist is empty', () => {
+    expect(isRegistrationEmailSuffixAllowed('user@example.com', [])).toBe(true)
+  })
+
+  it('isRegistrationEmailSuffixAllowed applies exact suffix matching', () => {
+    expect(isRegistrationEmailSuffixAllowed('user@example.com', ['@example.com'])).toBe(true)
+    expect(isRegistrationEmailSuffixAllowed('user@sub.example.com', ['@example.com'])).toBe(false)
+  })
+})